Supermodel Christie Brinkley has a one-in-a-million smile, but she is just one of millions who have benefited from today's preferred tooth-replacement technique: the dental implant. In a wide-ranging interview, Brinkley told Dear Doctor magazine about a helicopter accident she suffered while back-country skiing.

“I fractured two molars in the back of my mouth and I had to get two dental implants,” Brinkley told the magazine. “I am grateful for the dental implant technology that feels and looks so natural.”

You might think it serves little purpose to replace a missing back tooth that was barely visible in your smile to begin with — especially if you don't spend a lot of time posing for magazine covers. But this is actually not the case. Your molars are extremely important for chewing and even for maintaining a more youthful appearance.

Dentists generally agree that losing posterior (back) teeth can have many consequences for the remaining teeth and their surrounding structures, i.e., bone and gums. If back teeth are missing, the front teeth end up bearing more stress than they were built for. And there are certain things that happen when any tooth is lost, whether front or back, that can affect function and appearance.

For one thing, when a tooth is lost the adjacent teeth tend to drift into the empty space or tip towards it. This can adversely affect your bite. Too much shifting can render a tooth basically useless and also leave it more vulnerable to gum disease.

Another complication is the loss of tooth-supporting bone that inevitably occurs when teeth are lost. When a tooth comes out, the bone under it actually begins to melt away. Since back teeth support the vertical dimension of the face, their loss can cause what's known as “bite collapse” — a reduction in facial height that becomes increasingly noticeable over time and can make you look older.

A dental implant can prevent all of these things, while providing you with a replacement that looks and feels just like the tooth you lost.